package cn.hackcloud.mutithread.juc;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.atomic.AtomicStampedReference;

public class ABADemo {
    static AtomicReference<Integer> atomicReference = new AtomicReference<>(100);
    static AtomicStampedReference<Integer> atomicStampedReference = new AtomicStampedReference<>(100, 1);

    public static void main(String[] args) {
        new Thread(() -> {
            atomicReference.compareAndSet(100, 101);
            atomicReference.compareAndSet(101, 100);
        }, "t1").start();

        new Thread(() -> {
            try {
                TimeUnit.SECONDS.sleep(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(atomicReference.compareAndSet(100, 2019) + "\t" + atomicReference.get());
        }, "t2").start();
        try {
            TimeUnit.SECONDS.sleep(2);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("============以下是ABA问题解决==================");

        new Thread(() -> {
            System.out.println(Thread.currentThread().getName() + "\t第1次版本号:" +  atomicStampedReference.getStamp());
            try {
                TimeUnit.SECONDS.sleep(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            atomicStampedReference.compareAndSet(100, 101, atomicStampedReference.getStamp(),  atomicStampedReference.getStamp() + 1);
            System.out.println(Thread.currentThread().getName() + "\t第2次版本号:" + atomicStampedReference.getStamp());

            atomicStampedReference.compareAndSet(101, 100, atomicStampedReference.getStamp(),  atomicStampedReference.getStamp() + 1);
            System.out.println(Thread.currentThread().getName() + "\t第3次版本号:" + atomicStampedReference.getStamp());
        }, "t3").start();

        new Thread(() -> {
            int stamped = atomicStampedReference.getStamp();
            System.out.println(Thread.currentThread().getName() + "\t第1次版本号:" + stamped);
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            boolean result = atomicStampedReference.compareAndSet(100, 2019, stamped, stamped + 1);
            System.out.println(Thread.currentThread().getName() + "\t修改成功否:" + result + "\t第2次版本号:" + atomicStampedReference.getStamp());
            System.out.println(Thread.currentThread().getName() + "\t当前实际最新值" + atomicStampedReference.getReference());
        }, "t4").start();
    }
}
